Engineering topics

Hotzel, Grit

Publications and source records attributed to Hotzel, Grit.

4 records

DOE OSTI2014

Using analytic continuation for the hadronic vacuum polarization computation

We present two examples of applications of the analytic continuation method for computing the hadronic vacuum polarization function in space- and time-like momentum regions. These examples are the Adler function and the leading order hadronic contribution to the muon anomalous magnetic moment. We comment on the feasibility of the analytic continuation method and provide an outlook for possible further applications.

Feng, Xu↗

DOE OSTI2014

Four-flavour leading-order hadronic contribution to the muon anomalous magnetic moment

We present a four-flavour lattice calculation of the leading-order hadronic vacuum polarisation contribution to the anomalous magnetic moment of the muon, aμ hvp , arising from quark-connected Feynman graphs. It is based on ensembles featuring N f =2+1+1 dynamical twisted mass fermions generated by the European Twisted Mass Collaboration (ETMC). Several light quark masses are used in order to yield a controlled extrapolation to the physical pion mass. We employ three lattice spacings to examine lattice artefacts and several different volumes to check for finite-size effects. Including the complete first two generations of quarks allows for a direct comparison with phenomenological determinations of a μ hvp . The final result involving an estimate of the systematic uncertainty a μ hvp =6.74 (21)(18) 10 -8 shows a good overall agreement with these computations.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2013

Leading-order hadronic contribution to the anomalous magnetic moment of the muon from N_f=2+1+1 twisted mass fermions

We present results for the leading order QCD correction to the anomalous magnetic moment of the muon including the first two generations of quarks as dynamical degrees of freedom. Several light quark masses are examined in order to yield a controlled extrapolation to the physical pion mass. We analyse ensembles for three different lattice spacings and several volumes in order to investigate lattice artefacts and finite-size effects, respectively. We also provide preliminary results for this quantity for two flavours of mass-degenerate quarks at the physical value of the pion mass.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2013

Computing the hadronic vacuum polarization function by analytic continuation

We propose a method to compute the hadronic vacuum polarization function on the lattice at continuous values of photon momenta bridging between the spacelike and timelike regions. We provide two independent demonstrations to show that this method leads to the desired hadronic vacuum polarization function in Minkowski spacetime. We present with the example of the leading-order QCD correction to the muon anomalous magnetic moment that this approach can provide a valuable alternative method for calculations of physical quantities where the hadronic vacuum polarization function enters.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗